The present invention relates generally to a valve suitable for use as a service or shut-off valve. More particularly, the present invention relates to a valve having a one-piece formed valve body portion that is suitable for use in bi-directional valve applications and/or higher-pressure valve applications, such as those involving refrigerants. The invention also relates to a method for forming such a valve.
Ball valve and bi-directional ball valve assemblies for controlling the flow of fluids are known in the art. Conventional ball valves used in high-pressure applications commonly use a two-piece brass body in which the pieces are threaded or welded together to encapsulate a ball and associated ball seals. Certain other on-off ball valves, such as those used for lower-pressure applications wherein potential leaks are less dangerous (e.g., conducting water), have utilized a one-piece formed body to eliminate body joints and body seals. However, conventional one-piece body valves can typically only handle bi-directional bubble tight sealing in low-pressure applications. Sealing and leakage problems can occur with such prior single-piece body constructions when fluids having smaller moleculesxe2x80x94such as refrigerantsxe2x80x94are used at higher pressures. As such, there exists a need in the industry for a valve with a single-piece body construction that, among other things, (i) is relatively simple to construct using conventional materials and equipment, (ii) is dimensionally compatible with conventional systems, (iii) has sufficient fluid sealing characteristics, (iv) can be bi-directional, (v) can have body portions with various structural configurations, and (vi) is suitable for use in applications involving higher pressures.
The present invention recognizes the aforementioned challenges and the limitations associated with conventional one and two-piece valve body assemblies. The invention provides a valve having a one-piece formed body portion that is suitable for bi-directional and higher-pressure applications. The valve of the present invention utilizes a unique body portion construction that may be formed from a xe2x80x9ctubingxe2x80x9d using conventional forming techniques. The body portion is typically comprised of a metal, such as copper, aluminum, etc., but may also be formed of a plastic. Moreover, the valve of the present invention may be xe2x80x9cbi-directional,xe2x80x9d wherein it can generally seal pressure on either side of the valve.
Generally, higher-pressure applicationsxe2x80x94such as those used for refrigerationxe2x80x94commonly utilize a two-piece body construction, in which one or both of the body pieces is comprised of a relatively more expensive metal, such as brass. The one-piece body portion of the present invention provides a part with good functional and sealing characteristics, while eliminating the need for significant portions of the valve body to be comprised of brass components, which often involves higher overall component cost. Such a unitary valve body construction can permit the realization of significant cost savings. Further, the valve body portion can be readily produced using conventional manufacturing techniques without requiring significant capital investment, resulting in a valve assembly that is actually more versatile and less expensive to produce.
In accordance with a preferred embodiment of the present invention, a valve for controlling fluid flow is provided. The valve includes an actuating stem for controlling the flow of fluid through the valve; a valve member with a positioning formation and an opening for permitting fluid flow; a one-piece valve body portion; and at least one insert or compressor for retaining the valve member within the valve body portion. The valve body portion is comprised of a formable material, such as copper, and includes a first open end with a first diameter; a second open end with a second diameter that is sufficiently large enough to permit insertion of the valve member; a stem opening for receiving the actuation stem; and an internal member-receiving portion for receiving the valve member in proximity with the stem opening. The actuation stem is in communication with the positioning formation of the valve member and the flow of fluid through the valve is controlled by the orientation of the opening of the valve member within the internal member-receiving portion.